Field of the Invention
The invention relates to a surge arrester having a discharge element which is used to form a discharge current path, and is surrounded by a shield, which lengthens the creepage distance, with at least one shield composed of an electrically insulating material.
One such surge arrester is known, for example, from WO 98/38653. This document describes a surge arrester which has a discharge element through which a bracing element passes. The discharge element is provided with a connecting element at each of its ends. The discharge element is surrounded by an electrically insulating material, with a large number of shields being provided. The shielding lengthens the creepage distance between the connecting elements, thus increasing the withstand voltage.
During a discharge process, a comparatively high current is passed through the discharge element. This results in a large amount of heat being developed within a short time in the interior of the discharge element, and this must be emitted to the surrounding area.
If the discharge element is excessively heated, this can lead to irreparable damage to the surge arrester.